Convertible sealed reed switch relay

ABSTRACT

1. A convertible electromagnetic switching device comprising, in combination; a hollow insulating enclosing case; an electromagnet mounted within said case, said electromagnet including a coil having an axial opening therethrough, a magnetizable core extending through said axial opening, and a pair of magnetizable pole pieces overlapping the respective ends of said coil and said core and extending toward each other along opposite external sides of said coil; at least one opening in said case adapted to receive at least one magnetically operable-sealed switch means therein; at least one of said switch means removably inserted into said opening in said case to extend alongside of said magnetizable pole pieces at the opposite external sides of said coil of said electromagnet within said case to be operated upon energization of said electromagnet; and wherein said switch means inserted into said opening in said case comprises a magnetically operable-sealed reed switch unit mounted within an insulating housing to form a switch module, said housing having an external shape to be received by said opening in said case, a pair of wiring terminals secured to said housing to be accessible to the exterior of said enclosing case when said switch module is inserted into said opening therein, and means connecting the current carrying members of said reed switch unit to said pair of wiring terminals.

United States Patent [72] Inventors Lawrence EJ/an Horn Weukesha; itEdward Wayne "in, Milwaukee. both 01, Wis. 1211 Appl. No. 601,693 [22]Filed Dec. 14.1966 [45] Patented July 13.1971 [73] AssigneeCutIer-HammerJnc.

Mllwaultee,Wls.

($41 CONVERTIBLE SEALED REED SWITCH RELAY 15 Claims, 10 Drawing Pk:-

[52] 335/151, 317/101, 317l107,317/123 [51] 1nt.Cl 1101111/66, l-lOlh9/08 [50] 200/167; 335/73,151,152,153,154,162,197,17, 209, 220,81-86,132, 80;317/123, 101 CB, 101, 156', 340/376; 336/107 [5 6 I ReferencesCited UNITED STATES PATENTS 2,444,476 7/1948 Steam 340/376 X 2,902,5589/1959 Peek,1r.. 335/152 2,985,733 5/1961 Kamps.............. 335/2023,002,066 9/1961 Ketchledge et al.. 89/ 140 3,131,331 4/1964 Ray 317/1233,188,424 6/1965 Else et al. 335/152 3,190,985 6/1965 Pearse et a1335/152 X 3,234,738 11/1966 Zerfass 335/152 3,359,395 12/1967 Bruce335/152 X 3,121,147 2/1964 DalBianeoetal... 335/151 3,359,463 12/1967317/123 Primary Examiner-George Harris Assistant Examiner-R. N. EnvallAttorney-Hugh R. Rather CLAIM: I. A convertible electromagneticswitching device comprising, in combination; a hollow insulatingenclosing case; an electromagnet mounted within said case, saidelectromagnet including a coil having an axial opening therethrough, amagnetizable core extending through said axial opening, and a pair ofmagnetizable pole pieces overlapping the respective ends of said coiland said core and extending toward each other along opposite externalsides of said coil; at least one opening in said case adapted to receiveat least one magnetically operable-sealed switch means therein; at leastone of said switch means removably inserted into said opening in saidcase to extend alongside of said magnetizable pole pieces at theopposite external sides of said coil of said electromagnet within saidcase to be operated upon energization of said electromagnet; and whereinsaid switch means inserted into said opening in said case comprises amagnetically operable-sealed reed switch unit mounted within aninsulating housing to form a switch module, said housing having anexternal shape to be received by said opening in said case, a pair ofwiring terminals secured to said housing to be accessible to theexterior of said enclosing case when said switch module is inserted intosaid opening therein, and means connecting the current carrying membersof said reed switch unit to said pair of wiring terminals.

A 1, Ill/I I II PATENTEU JUL 1 3 IBM SHEET 1 IF 5 LLJ PATENTEH JUL 1 3mr.

SHEET 2 BF 5 an 3 QM wv w v on N. i 3 n M 1 v v w m I W E N. 5 a E: W\ Qm 1 um m 1 m w m I 9 L v Q Q .\N \W Q 00W MQ\ & Q wm\ am 3% Q a? Q3 mm Nvv um mm 8 M Q 9v wm vm w mm L A a QM PATENTEU JUN 31% SHEET 3 PF 5PATENTEU JUL 1 3 I97? SHEET BF 5 lllli ll NN 3v mm N S PATENTED JUL 13197i SHEET S BF 5 CONVERTIBLE SEALED REED SWITCH RELAY This inventionrelates to electromagnetically operated relays and more particularly tosuch relays which utilize sealed reed switches to make and break thecircuits.

While not limited thereto the relay of this invention is particularlysuitable for industrial control applications such as on machine toolsand other types of machinery.

The numerous advantages of sealed reed switches render them extremelydesirable in design approaches of such relays where the present demandscall for reduced size and greater life and reliability. The presentrelay incorporates standards and conventions accorded the prior artmachine tool relays and in so doing, has various features which areunique to reed relay constructions.

It is therefore a primary object of this invention to provide anelectromagnetic relay designed for industrial control applications whichutilizes sealed reed switches as the switching pole elements.

It is another object of this invention to provide an electromagneticrelay of the sealed reed switch type wherein the reed switch poles arelocated externally of the coil and a laminated steel core is locatedwith in the central opening of the coil.

It is another object of this invention to provide an electromagneticrelay of sealed reed switch application having modular constructionwherein the individual reed switch poles may be read y replaced in thefield.

It is another object of this invention to provide an electromagneticrelay of the sealed reed switch type which requires a minimal panel areafor mounting and has from accessibility for removing the switch polesand for the wiring terminals.

It is further object of this invention to provide an electromagneticreed relay which may be of standard or latched type operation whereinthe reed switch pole elements may be readily changed from normally opento normally closed, or vice versa.

It is still a further object of this invention to provide anelectromagnetic relay capable of operating on either AC or DC supply andwherein a rectifier unit necessary for AC use is readily replaceable.

It is still another object of this invention to provide a read relayhaving mechanical means to indicate the operational state that the relayis in.

Other objects and advantages will be pointed out in, or be apparent fromthe following specification and claims when read in conjunction with theaccompanying drawings wherein:

FIG. 1 is a front elevational view of the relay of this invention;

FIG. 2 is a cross-sectional view taken along line 2 2 of FIG. 1 showingthe general side profile of the relay and the orientation of the switchpole units within the relay;

FIG. 3 is a front elevational view of a modified version of the relay ofthis invention;

FIG. 4 is a cross-sectional view taken along line 4-4 of FIG.

FIG. 5 is a cross-sectional view taken along line 5-5 of FIG. 3;

FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. 3;

FIG. 7 is a cross sectional view taken along line 7-7 of FIG.

FIG. 8 is an exploded isometric view of the various parts utilized tomake up a coil pole unit;

FIG. 9 is an exploded isometric view of the various parts used to makeup a desired switch pole unit; and

FIG. 10 is a circuit diagram of one of the parts shown in the coil poleunit of FIG. 8 and its connections to the coil.

The relay shown in FIGS. l and 2 is a standard relay having normallyopen and normally closed switch poles operable to their closed and openconditions, respectively. by energizing the coil and returnable to theiroriginal conditions upon deenergization of the coil. The relay shown inFIGS. 3 through 7 is a latched type of relay also having both types ofswitch poles. but all of which require energization of a second coil,wound in a reverse direction, to return the switches to their originalconditions. The standard and latched relays are physically quite similarwith only minor detail differences to the base, coil and one of themagnetic pole pieces. These differences will be specifically mentionedin the following description while for the most part the descriptionwill be applicable to both versions.

The relay has an enclosing case, or boxlike base 2, made of a plasticinsulating material with a central cavity open to the front and rear. acentral web extends across the front opening between the sidewalls toform a front wall 2a which divides the opening into upper and lowerswitch pole receiving openings. Each of these openings is divided intofour separate switch pole receiving pockets by ribs 2b which extendalong the side and rear walls of the base. A central opening 2: isprovided in the rear wall of base 2 which is of corresponding size andalignment with the front wall 20. Opening 2c also extends into theportion of the rear wall which is in corresponding alignment with theupper right-hand switch pole receiving pocket for the standard relay ofFIG. 1 and extends into the portions of the rear wall which are inalignment with both the upper and lower right-hand switch pole receivingpockets of the latched relay of FIG. 3. The base 2 is also provided witha pair of inwardly projecting ribs in! (FIGS. 6 and 7) which extendalong one sidewall from the opening 2c to the inner surface of the frontwall 20. The front wall 20 has a window 2: formed therein, one edge ofwhich lies adjacent one of the sidewalls of the base 2, and atransparent plastic lens If is secured over the window 2: by anysuitable method, such as glueing. In addition, the wall 20 has acentrally located threaded opening 23 and a plurality of various shapedrecesses along its upper and lower edges, each recess being in alignmentwith a pole receiving pocket. The shape of the recesses provide keywaysto prevent the insertion of an improper pole unit into the respectivepocket. Each of the keyways is further provided with a threaded openingin its bottom surface to receive a screw held by the pole unit to securethe unit within the pocket as will become more apparent in laterdescription. It may be seen by comparing FIGS. 1 and 3 that the keywayarrangement varies between the standard and latched relay as will becomemore apparent in later description.

A first U-shaped pole piece 4 is inserted, bight portion first, intobase 2 through opening 2: until such portion thereof engages the innersurface of front wall 20. The bight portion is cut back somewhat at oneend to clear the ribs 2d while the legs thereof engage the opposed outersides of the ribs to position the pole piece within the base. The bightportion of pole piece 4 is also cut back at the opposite end to providetravel clearance for an indicator member as will be more fully describedlater. Each leg of pole piece 4 is divided by slots 44 into fourindividual legs, each of which are in alignment with a respective polereceiving pocket.

A molded coil-element 6 is next inserted through opening 2c until theend thereof bears against the bight of pole piece 4. The coil isprovided at the rear most end with a foot portion 60 (see FIGS. 5, 6and'l) which extends to one side to lie within the opening of the upperright-hand pocket of base 2 for the standard relay. An additional,oppositely extending foot 6b is provided for the latching relay, thefoot 6b extending into the opening of the lower right-hand pocket ofbase 2. The coil for the standard relay has a single coil winding 6c,the ends of which are connected internally to the male halves of a pairof plug-in type connectors M which extend upwardly from foot 60. Thecoil 6 for the latching relay is a double-coil element having a somewhatsmaller "operate" winding 6: connected internally to the male connectors6d of foot 60, and a "release" winding 6] wound in the oppositedirection of the operate winding, the ends of which are connnected tomale connectors 63 extending upwardly from foot 6b. Each foot 6a and 61)has a slot 6h molded into its upper surface between the upstanding prongmembers.

The coil 6 is an elongated member with a central opening extending fromend to end. A core is provided for the coil 6 by inserting a loose stackof steel laminations 8 into the central opening from the rear of therelay. The length of the lamina tions is just slightly greater than thelength of the coil so that the laminations bear against the bights ofpole piece 4 and a second pole piece 10 which is inserted over the rearend of coil 6.

Pole piece I is a U-shaped member similar to pole piece 4 and isinserted into the relay with its legs entering first to extend along thecoil 6 toward the rearwardly extending legs of pole piece 4. The bightof pole piece I0 is also cut back at one end to clear the positioningribs 2d while its legs engage the opposed outer sides of the ribs toposition the member. The legs of pole piece 10 are divided by slots 10ainto four individual legs which are aligned with the legs of pole piece4. The other end of pole piece 10 is cut away at one side thereof toclear the foot 60 of coil 6 for the standard relay and cut away straightacross the end to clear both feet 60 and 6b of the latching relay. Withparticular reference to FIG. 4 it can be seen that in cutting away theend of pole piece I0 to clear the feet 6a and 6b of coil 6, theright-hand individual legs thereof have also been removed. In thestandard relay where it is only necessary to provide clearance for thefoot 6a, only the upper right-hand individual leg member is removed. Itcan also be seen that the center pair of legs of each pole piece aresomewhat shorter than the end legs thereof so that in their assembledpositions within the cavity the airgap between the cooperating centerlegs is greater than the gap between the cooperating pairs of outerlegs. This produces a more even flux density within each pole pocket,while slotting the pole piece legs into individual legs concentrates theflux within the pole pocket areas and decreases the eddy currents of thepole pieces 4 and 10 to provide a faster pickup and dropout time for theswitch poles.

The coil and pole piece assembly is held fast within the base by placinga leaf spring l2 against the pole piece 10 and securing the base to amounting plate I4 by rivets 16 which are received within openings in aplurality of feet 2/: on base 2. Mounting plate I4 has an arrangement ofholes therein for mounting the relay to a panel. The central portion ofspring 12 engages the pole piece I0 and is positioned by a pair ofdepending bosses [0b on the pole piece [0 which inter'fit withcorresponding notches formed on the edges of spring 12. The outer endsof spring 12 are bent away from the pole piece [0 to engage the platel4. Upon assembly of the plate 14 to the enclosing case, or base 2, thespring 12 is compressed between the plate and the pole piece 10 to biasthe electromagnet assem bly tightly against the web, or front wall 20.

Base 2 is also provided with a mechanical indicator assembly (see FIG.which consists ofa long spring member 18 having a tab formed at one endby bending a portion of the end at right angles to the member I8. Thespring 18 has a mounting portion 18a formed at its other end consistingof a pair of wings extending angularly and transversely to the springmember. The portion 18a is forced within a linear slot 2k in the rearend of one of the sidewalls of base 2 to secure that end to the base bycompressing the wings flat so that the spring 18 extends along the walland into the window 2e. The tab of spring 18 receives a colored plasticsleeve 18b to provide an easily visible indicator through the lens 2].The spring 18 also has a strip of magnetizable material 1&- secured toits central portion to serve as an armature which is attracted to thecut back bight of pole piece 4 upon energization of the coil 6, therebymoving the colored indicator 18b to the left-hand position within thewindow 2e to indicate the energized state of the relay. The springmember I8 returns the indicator 18b back to the original right-handposition in window 22 upon deenergization of coil 6. The strip 180 isreplaced by a permanent magnet member of similar dimensions in thelatching relay which causes the indicator to remain in the left-handposition in response to an operating pulse and be released to theright-hand position in response to a reversely directed pulse by therelease winding.

As so far described the relay is a factory assembled device comprisingthe enclosing case an electromagnet assembly which is purchased as aunit with individual switch and rectifier modular elements assembledthereto. These elements may also be individually purchased to replace orbe added as desired within certain limits as set forth by the keywaycombinations of the front surface 2a of the base. The electromagnetassembly within the enclosing case divides the central cavity into twoindividual cavities, each aligned with the respective front opening oneither side of the central web 20 to receive the various modularelements. The standard relay (FIG. 1) requires one coil pole module CPand has provisions for seven switch pole modules of either the normallyopen type NO or the normally closed type NC with a limit of fivenormally closed modules. The latched relay (FIG. 3) requires two coilpole modules and has provisions for six switch pole modules of eitherthe normally open latched type N01. or the normally closed latched typeNCL with no limits as to either type.

With reference to FIG. 8, the various parts used to make either of twotypes of coil pole modules are shown in exploded isometric relation. Thecoil pole module CP consists of a pair of complemental housing halves 20and 22, which are generally symmetrical externally, and a barrier member24 which is sandwiched between the housing halves at their lower end.The housing halves 20 and 22 and barrier 24 are made of an insulatingplastic material. The inside faces of members 20 and 22 and oppositefaces of barrier 24 are formed with numerous interfitting andcomplemental bosses and recesses to position and trap the currentcarrying elements according to conventional manufacturing techniques,therefor such positioning will only briefly be described.

A pair of female stab-on connectors 26 and 28 are provided with notches26a and 280, respectively, in each leg of their U- shaped body portions.The connector 26 is entrapped between the housing half 20 and thebarrier 24 with its bight portion abutting a ridge 20a on housing half20 and the notches 26a intert'itting with a complementally formed boss20b on housing 20 and a similar boss on barrier 24. Likewise, connector28 is entrapped between barrier 24 and housing half 22 with its bightportion against a ridge 240 formed on barrier 24 and its notches 28aengaging a complementally formed boss 24b on barrier 24 and a similarboss on housing 22. To position the barrier 24 within the housings 20and 22, the barrier is provided with a T-shaped lateral extension 24c,the crosshead of which fits snugly into respective grooves in thehousing members. The barrier 24 is also provided with a tapered leg 24dwhich depends beyond the lower ends of the housing members.

A pair of substantially L-shaped screw receiving terminal plates 30 and32 are each provided with a notch and wing configuration along theiredges to interfit with complementally shaped ledges and recesses in thehousing halves 20 and 22 and be entrapped therebetween with the screwreceiving portions extending outwardly of the housings. Each of thehousing halves 20 and 22 have one half of a key formation at their upperends, each half of the key being provided with a semicircular openingwhich becomes a circular hole upon assembly of the two halves. A screwhaving a reduced shank diameter is rotatably captivated within theopening to be threaded into the corresponding opening within the keywayupon insertion of the unit into the pocket. The key for the coil poleunit, when assembled, is substantially the male portion ofa dovetailarrangement which will only fit into a correspondingly dovetailed keywayin the base 2.

The housing halves, with the various parts held therebetween, arepreferably secured together by sonic welding. Each housing half 20 and22 also has a stepped recess 20: and 22c, respectively, along the lowerportion of their mating edge (FIG. 8) which forms a secondary keyway forthe coil pole module when the halves are assembled. The secondary keywayfor the coil pole module when the halves are assembled. The secondarykeyway surrounds a complemental ridge, or key, 2j in the coil polereceiving pocket of base 2 to allow that module to be fully insertedtherein (FIGS. 5 and 7). The switch pole modules, to be described later.do not have the secondary keyway formed therein and therefore abut thetop edge of the ridge 2j to prevent their complete insertion into apocket designed to receive a coil pole module.

Electromagnetic relay coils generally require a direct cur rent input tooperate at a steady value. particularly relays of the reed switch type.If the supply current to the relay is to be DC, a DC coil pole module isprovided by soldering a first conductor between terminal 30 andconnector 26 and another conductor between terminal 32 and connector 28.The coil pole module is then inserted into the base until thefirst, orupper. key seats with the mating keyway and is held there by turning thecaptivated screw into the corresponding threaded opening in the keyway.When the coil pole CP is so inserted the female connectors 26 and 28engage the respective prong terminals of the coil to provide electricalconnection therebetween and the terminals 30 and 32 receive pressureplates and binding screws to secure conductor leads from the supplysource. The tapered leg 24d of the barrier 24 extends down into thegroove 6] to provide additional insulation between the prong and bladeconnections to the coil.

For the installation where the supply current to the relaywis to be AC,a rectifier package 34 is added to the coil pole module. The barrier 24has a pocket 24c open to its upper end which receives a projection 340depending from the rectifier package to position the latter within thehousings. The housing halves and 22 also have ledges which overhang thepackage 34 to further entrap the package therebetwecn. The wire leads ofthe rectifier package 34 are in turn welded tothe various terminals inthe manner shown in the circuit diagram of FIG. [0. The wiring terminals30 and 32 are connected to the input terminals of a full wave rectifierbridge RE. the output terminals of which are connected to the connectors26 and 28. A zener diode ZD is connected in series between an outputterminal of bridge RB and the terminal 16 and is poled to oppose thecurrent direction to effectively brake the induced current flow upondeenergization to provide a faster dropout time for the relay. Theelements of the package 34 may be molded in epoxy resin or the like tothe proper shape so that the package may be easily assembled in the coilpole module. Providing the coil rectifier in a separate, removable unitsuch as the coil pole CP is a definite advantage to the customer as ithas been found that the source of coil faults are commonly failure ofarectifier. Upon such a failure, the customer need only replace the coilpole module instead of the entire coil, which is a much simpler and lessexpensive operation.

The various switch pole modules that are used for the two types ofrelays are physically very similar. The parts shown in the explodedisometric view of HG 9 represent the parts which may be used to make anyof the required polar. Each switch pole module is made up of two housinghalves 40 and 42. the exterior shapes of which are very similar to thehousing halves 20 and 22. The housings have notches 40a and 424 formedin one wall to form a window. when assembled, to expose a sealed reedswitch unit 44 positioned inside. The reed switch units shown in thedrawings are merely exemplary of a type of reed switch to be used. Aparticular reed switch of the type described and claimed in the .I. A.Bongard and MR. Swinehart copending application Ser. No. 528,240, nowUS. Patv No. 3.327.262 and assigned to the assignee of this invention.has been found to be desirable for use in the relay disclosed herein.

A screw receiving wiring terminal 46 is secured to one of the extendingreeds of switch unit 44, and the other extending reed thereof has aconducting strap 48 secured to it to extend along the reed switch to apoint just below the terminal 46 where a second wiring terminal 50 issecured to the strap 48.

The terminals 46 and 50 are similar to the terminals 32 and 30.respectively, and similarly intertit within the housing halves 40 and 42to secure the upper end of reed switch 48 in place. An insulating sleeve38. of rubber, heat shrinkable material. or the like, is disposed aroundthe upper end of the reed switch to surround the exposed portion of thereed between the glass enclosure and the terminal 46. A similar sleevemay be added to the lower end of the switch if the usage of the devicerequires additional insulating qualities. A slot such as at 42b (FIG. 9)is provided in each housing half to receive the extending end of thelower reed to thereby position the lower end of the switch within thehousing. A leaf spring 52 is entrapped within grooves of the housings toextend outwardly of one side of the switch pole unit to bear against thesidewall of base 2 upon insertion of the switch pole module into thebase. the spring 52 thereby urging the lower, or inner. end of themodule into close proximity with pole piece 10.

The switch pole module as herein described is a normally open switch andis secured together by sonic welding. as was the coil pole module, andsimilarly has a screw captivated in the key formed at the upper end ofthe housing. The key for the normally open switch pole unit whenassembled is a semicircular one as shown in dotted lines in the lowerrow of pole units of FIG. 1, and is received by any of the three typesof keyways of the base 2. However, as mentioned earlier. the secondarykey 2j of the coil pole pockets prevents the insertion of the NO switchmodule therein. The normally open switch module is shown in itsassembled position with respect to the base 2 in the lower portion ofFIG. 2.

With further reference to FIG. 9, a biasing permanent magnet assembly 54may be added to the aforedescribed switch pole module to achieve eithera normally closed. normally open latched. or normally closed latchedswitch pole version. Magnet assembly 54 comprises a pair ofpermanentmagnets 56 and 58 secured to a steel strap 60 and positionedwithin pockets 40c and 42c of housing halves 40 and 42, respectively, tolie along side of the glass enclosure of the reed switch and on the sidethereof opposite to the coil. The different operating modes are achievedby poling the bias magnet assembly 54 in different directions and bydifferent choices of permanent magnet materials which produce differentflux output levels.

To provide a normally closed switch pole module NC, the magnet assembly54 is poled to provide a flux path within the reed switch unit 44 thatwill be opposite in direction to the flux path of the "operate" coil 6cwithin the reed switch when the module is inserted into the relay base.The magnet assembly 54 for the normally closed version is made ofmagnets 56 and 58 which are made from Alnico 8 or the like to produce aflux of sufficient strength to operate the reeds of switch unit 44 ofits own accord, and therefor the fluLOf the assembly 54 must becancelled by the flux of the operate" coil upon energization thereof tocause the reeds to drop open.

To provide a normally open latched switch pole module NOL, the magnetassembly 54 is poled to provide a flux path within the reed switch 44that will be in the same direction as that provided by the operate" coil6:. In this instance the magnet assembly 54 has magnets 56 and 58constructed of Alnico 5 or the like to produce a flux of a strengthwhich is not sufficient to operate the reed switch of its own accord.but is sufficient to hold the reeds closed once they are operated by theenergized "operate" coil 6e. The release" coil 6fcreates an opposingflux path within the switch unit 44 upon energization to effectivelycancel the flux of the biasing magnet assembly therein to cause thereeds to open.

To provide a normally closed latched switch pole module NCL. the magnetassembly 54 is poled to provide a flux path within the reed switch unitwhich is opposite to that provided therein by the energized operatecoil. In this instance. the magnet assembly 54 again uses magnets 56 and58 made from Alnico 5 or the like to-produce a flux of insufficientstrength to operate the switch reeds of its own accord. but is ofsufficient strength to hold them closed when they are operated by therelay coil. The switch 44 is initially closed in this version afterinsertion into the relay base by pulsing the "release" coil 6f whichprovides a flux path within the switch which cooperates with that ofthebiasing magnet assembly 54, and the two paths add to provide sufficientmagnetic strength to close the reeds. The flux provided by the energized"operate" coil is opposite to that of the permanent magnet assembly 54and cancels the biasing flux to open the contacts.

In each switch pole module where the biasing magnet assembly 54 isemployed it is necessary to provide a magnetic shield for the unit toprevent stray flux patterns from affecting adjacent switch units. Tothis end, a pair of thin steel straps 62 are secured within recesses 40dand 42d formed in the exterior surfaces of housings 40 and 42,respectively, by riveting over projections 40: formed on the housing 40and which are received by holes 62a of strap 62. While only one strap 62is shown in FIG. 9 for representative purposes, it is to be understoodthat a shielded switch module has two straps 62, one for each housinghalf as can be seen in the cross-sectional view of FIG. 7. The keyportion for each switch pole module having the biasing magnet assembly54 is substantially a triangular member as shown in dotted lines in theupper row of pole modules in FIG. I, and will fit only in the triangularkeyways of base 2, thereby controlling the number and location of thebiased pole modules with respect to the standard relay of FIG. 1.

A plastic dummy pole member 64 is provided to be used in pockets notrequiring a switch module and is shown in one of the pockets of thelatched relay, particularly FIGS. 3 and 5. Member 64 is somewhatsimilarly shaped to the upper halfofa switch or coil pole module, havinga semicircular key which is received by any of the keyways. A boss 64adepends from the key to extend into the threaded opening of the keywayto help position the upper end of the member. The lower end of member 64extends just slightly into the pocket to position the lower end thereof.

A cover plate 66 is placed over the front of the relay and secured inplace by a screw which takes into the central threaded opening 2g ofbase 2. The plate 66 overlies all of the keyways of base 2 to cover thescrews holding the switch pole modules down and bears inwardly against aportion of the dummy pole 64 to further hold it in place and to preventis accidental removal. An opening is provided in plate 66 to allow thelens 2fto extend therethrough and suitable inditia may be provided onthe cover plate adjacent the lens opening to aug ment the indicatormember 18b.

The extensive use of plastic throughout the relay allows the variousparts to be easily and inexpensively colored to provide a color codingto depict the functions of the various parts. As a preferred example,the base is colored gray in keeping with most electrical equipmentenclosures and cases today. The enclosing case, or base 2, of thestandard relay is a darker gray, such as charcoal, than is the base ofthe latched relay. The coil pole module housings 20 and 22 are coloredblue for the strictly DC coil pole, while the AC-DC pole module housingsare colored red. The switch pole modules are also colored according tofunction, the normally open pole module NO having green housing halves40 and 42, the normally closed pole module NC having yellow housinghalves. For latched poles NOL and NCL, one of the housing halves islight gray as is the base while the other housing half is either greenfor the normally open or yellow for the normally closed.

Thus there is provided a panel mounted sealed reed switch relay ofunitized construction, the parts of which may be readily replaced tovary the operating mode or replace a defective unit. It is to beunderstood that the aforedescribed relay is merely exemplary of onepreferred construction and is not intended to limit the scope of theappended claims.

We claim:

1. A convertible electromagnetic switching device comprising, incombination; a hollow insulating enclosing case; an electromagnetmounted within said case, said electromagnet including a coil having anaxial opening therethrough, a magnetizable core extending through saidaxial opening, and a pair of magnetizable pole pieces overlapping therespective ends of said coil and said core and extending toward eachother along opposite external sides of said coil; at least one openingin said case adapted to receive at least one magnetically operablesealedswitch means therein; at least one of said switch means removablyinserted into said opening in said case to extend alongside of saidmagnetizable pole pieces at the opposite external sides of said coil ofsaid electromagnet within said case to be operated upon energization ofsaid electromagnet; and wherein said switch means inserted into saidopening in said case comprises a magnetically operable sealed reedswitch unit mounted within an insulating housing to form a switchmodule, said housing having an external shape to be received by saidopening in said case, a pair of wiring terminals secured to said housingto be accessible to the exterior of said enclosing case when said switchmodule is inserted into said opening therein, and means connecting thecurrent carrying members of said reed switch unit to said pair of wiringterminals.

2. The combination according to claim 1 together with permanent magnetmeans secured within the housing of said switch module adjacent saidswitch unit and on a side thereof opposite said electromagnet when saidmodule is inserted in said opening in said enclosing case, and whereinsaid permanent magnet means produces a magnetic flux path within saidswitch unit to bias the magnetically operable contacts thereof.

3. The combination according to claim I together with a connector moduleinserted into said opening in said case to provide a readily removableelectrical connection to said electromagnet, plugin electrical connectormeans mounted on said coil and cooperating plug-in electrical connectormeans mounted on said connector module in engagement with said connectormeans on said coil, a pair of wiring terminals secured to said connectormodule to be accessible to the exterior of said enclosing case when saidconnector module is inserted into said opening therein, said connectormodule having an outwardly extending key formed thereon to becooperatively received within a complementally formed recessed keyway insaid case, and having a secondary keyway formed therein to cooperatewith an outwardly extending secondary key formed in said enclosing case,said secondary key being of a form preventing insertion of said switchmodules therein.

4. The combination according to claim 2 together with a pair of shallowrecesses formed in opposite external sides of those switch modulehousings in which permanent magnets are mounted, projections extendingoutwardly from said recesses and a pair of magnetizable members securedwithin said recesses at opposite external sides of said switch modulehousings by deforming said projections over outer surfaces of saidmagnetizable members to provide self-contained mag netic shielding foreach switch module.

5. The combination according to claim I wherein said insulating housingof said switch module has a lateral opening formed therein on the sideadjacent said pole pieces of said electromagnet to expose a portion ofsaid switch unit directly to said electromagnet.

6. An electromagnetically operated multipole convertible reed relaycomprising, in combination; a hollow insulating enclosing case; a coilmounted in said case to extend axially front to rear of said case; anaxial opening in said coil; a magnetizable core in said opening in saidcoil and extending end-to-end of said coil; a pair of U-shapedmagnetizable pole pieces overlapping the opposite ends of said coil andextending toward each other along the opposite exterior sides of saidcoil; openings in the front of said enclosing case on opposite sides ofsaid coil; and a plurality of individually removable switch modulesinserted within said openings in said case to extend into said casealongside of said pole pieces at the exterior sides of said coil, eachof said switch modules comprising a molded insulating housing, a sealedelectromagnetically operable reed switch mounted within said housing, apair of wiring terminals carried by said housing at a forward end toextend out of said enclosing case. and means connecting said wiringterminals in the respective contacts of the reed switch mounted withinthe housing I The combination according to claim 6 wherein the insulating housing of each of said switch modules has a lateral openingformed therein on the side ad acent said pole pieces of saidelectromagnet to expose a portion of said reed switch unit directly tosaid electromagnet 8. The combination according to claim 6. togetherwith an indicator member mounted within said case to extend along oneside of said electromagnet and into a window formed in an exteriorsurface of said case, said indicator being movable toward and away fromsaid electromagnet. means to bias said indicator away from saidelectromagnet to a first position within said window, and wherein saidindicator is attracted to said electromagnet upon energization thereofto cause said indicator to move to a second position within said window9. The combination according to claim 6. wherein the winding ends ofsaid coil are terminated at plug-in type electrical connector means,first portions of said connector means being secured to an exteriorsurface of said coil and exposed within one of said pockets of saidcase, second cooperating portions of said connector means secured to aninsulating housing removable inserted into said pocket, said housingfurther having a pair of wiring terminals secured thereto exposed to theexterior of said case when said housing is seated within said pocket,and conductor means electrically connecting said other portions of saidconnector means to said wiring terminals within said housing.

Ill. The combination according to claim 9, wherein said conductor meanscomprises rectifier means for rectifying supply alternating current toprovide energizing direct current for said coil, said rectifier havingits input terminals connected to said wiring terminals and its outputterminals connected to said second cooperating portions of saidconnector means.

II. The combination according to claim 10, wherein said rectifier meansis a full-wave rectifier bridge and further comprises a zener diodeconnected between an output terminal of said rectifier bridge and theassociated other portion of said connector means to be in series withsaid coil and oppose the coil current when electrically connectedthereto.

12. The combination according to claim 6, wherein said core comprises aplurality of magnetizable laminations loosely stacked within the centralopening of said coil.

13. [n a convertible electromagnetic switching device, the combinationcomprising:

an insulating enclosing case having a cavity with openings to oppositeends thereof, a central web extending across a first open end of saidcase to divide the opening therein into a pair of openings. and a pairof inwardly extending wall portions at the second open end of said caseto reduce the opening therein;

a first magnetic pole piece inserted within said cavity from said secondend to abut said central web and having portions extending toward saidsecond end;

a coil member inserted within said cavity from said second end to abutsaid first pole piece between said extending portions, a central openingin said coil member aligned with said opening in said second end of saidcase and extending through said coil to open to said first pole piece;and at least one foot portion extending outwardly of said coil member,said foot portion having plug-in electrical connectormeans secured to anexterior surface thereof and connected to the windings of said coil,said connector means being in alignment with a respective one of saidpair of openings of said case and within said cavity thereof.

a core comprising a plurality of loosely stacked magnetizablelaminations nserted within said central opening of said coil throughsaid opening in said second end of said case. said core abutting saidfirst magnetic pole piece;

a second magnetic pole piece inserted within said cavity from saidsecond end to abut an opposite end of said core, said second magneticpole piece aving portions extending along opposite sides of said coiltoward said extending portions of said first pole piece and in alignmenttherewith.

a mounting plate for mounting said switch device to a panel secured tosaid second end of said enclosing case to close the opening therein;

biasing means disposed within said opening in said second end. saidbiasing means being compressed between said mounting plate and saidsecond magnetic pole piece to bias said magnetic pole pieces. core andcoil tightly against said central web within said cavity;

means removably inserted into said cavity through a respective one ofsaid openings in said first end to cooperatively engage said connectormeans for electrically connecting said coil winding to an energizingsupply source; and

least one magnetically operable switch module removably inserted intosaid cavity through either of said openings in said first end to beoperated upon energization of said coil.

14. In combination, an operating coil for an electromagneticallyoperable switching device and a plug-in connector module for connectingsaid coil to an electrical supply source, said coil having plug-inelectrical termination means exposed to an exterior surface thereof andsaid connector module including an insulating housing, plug-in connectormeans supported on said housing, wiring terminal means supported on saidhousing, and a full wave rectifier bridge within said housing, saidbridge having its input terminals connected to said wiring terminalmeans and its output terminals connected to said plug-in connectormeans, and wherein an electrical supply source is connected to saidwiring terminals on said connector module and the latter is connected tosaid coil by means of cooperable plug-in engagement between said plug-inconnector means on said module and said plug-in termination means onsaid coil to supply rectified current to said coil.

15. A convertible electromagnetic switching device com prising incombination; a hollow insulating enclosing case; an electromagnetmounted within said case, said electromagnet including a coil having anaxial opening therethrough, a magnetizable core extending through saidaxial opening and a pair of magnetizable pole pieces overlapping therespective ends of said coil and said core and extending toward eachother along opposite external sides of said coil; at least one openingin said case adapted to receive at least one magnetically operablesealed switch means therein, at least one of said switch means removablyinserted into said opening in said case to extend alongside of saidmagnetizable pole pieces at the opposite external sides of said coil ofsaid electromagnet within said case to be operated upon energization ofsaid electromagnet, and an indicator member mounted within said casealongside said electromagnet for removing toward and away from saidelectromagnet, said indicator member having a portion extending beyondsaid electromagnet and into a window opening formed in said case, meansfor biasing said indicator member to a first position within saidwindow, and wherein said indicator is attracted to said electromagnetupon energization thereof to cause said portion within said window tomove to a second position therein against the bias of said biasingmeans.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3, 1Dated July 13, 1971 lnventofls) Lawrence E. Van Horn t a1 It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

On the cover sheet [54] "15 Claims" should read 18 Claims Column 1, line25, "with in" should read within line 36, after "is" insert a Column 3line 69, after "bight" insert portion Column; 5, lines 2 to 4, cancel"The secondary keyway for the coil pole module when the halves areassembled.". Column 7, line 43, "is" should read its Column 9, line 24,"removable" should read removably Column 10, after line 66, insert thefollowing claims:

-16. Ina relay the combination comprising: an

operating coil defining opposite, parallel sides; a

plurality of modular switch units assembled with the coil,

each switch unit comprising an elongated case with a reduced bodyportion and an enlarged head presenting a pair of forwardly facingterminals which are stepped upwardly from front to rear, each switchunit including an elongated, magnetically operable reed switch disposedin the body portion of the case with one end near the head, there beinga connector between said one end of the switch and one of the terminalsand a second connector leading from the other end of the switch to theother terminal, which second connector is disposed in the case alongsidethe EM PO-IOSO (10-69) USCOMM-DC 60376-P69 U.ST GOVERNMENT PRINTINGOFFICE: 9'9 D-SlB-JS UNITED STATES PATENT OFFICE CERTIFICATE OFCORRECTION Patent No. 3 593 Z31 Dated July 13 1971 2 Inventor) LawrenceE. Van Horn 81; 1 PAG It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

switch, switch units being arranged in banks which face respective sidesof the coil, each bank comprising a plurality of switch units in analigned, side-byside relationship, the two banks being in an alignedrelationship with the backs of the two banks facing one another and withthe heads of the units of both banks all on the same side of the coilbut with the heads of the units of the two banks facing outwardly inopposite directions, the switches all being axially aligned with thecoil to be operable thereby; and housing means to releasably hold theswitch units and coil in assembled relationship,--

)RM F o-1050 (10-69) USCOMM-DC 60376-pqg U.5. GOVERNMENT PRINTING OFFICEI965 CIS66-33| UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTIONPatent No. 3 593 231 Dat d July 13 1971 Lawrence E. Van Horn et a1 .PAGE3 Inventor(s) It is certified that error appears in the above-identifiedpatent and that said Letter s Patent a hgreby corrected as shown below--l7. The combination of claim 16 wherein there are a plurality ofaligned pairs of elongated magnetic flux concentrator plates, one pairbeing adjacent each switch with the members of the pair parallel to andassociated with respective reeds to define a magnetic flux path acrossthe magnetic gap of the switch.--

--l8. The combination of claim 17 wherein the pairs of concentratorplates each comprise an upper member at one end of the coil and a lowermember at the other end of the coil; and the upper ends of all the uppermembers are magnetically connected; and the lower ends of all of thelower members are magnetically connected.

Signed and sealed this 23rd day of May 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents

1. A convertible electromagnetic switching device comprising, incombination; a hollow insulating enclosing case; an electromagnetmounted within said case, said electromagnet including a coil having anaxial opening therethrough, a magnetizable core extending through saidaxial opening, and a pair of magnetizable pole pieces overlapping therespective ends of said coil and said core and extending toward eachother along opposite external sides of said coil; at least one openingin said case adapted to receive at least one magneticallyoperable-sealed switch means therein; at least one of said switch meansremovably inserted into said opening in said case to extend alongside ofsaid magnetizable pole pieces at the opposite external sides of saidcoil of said electromagnet within said case to be operated uponenergization of said electromagnet; and wherein said switch meansinserted into said opening in said case comprises a magneticallyoperable sealed reed switch unit mounted within an insulating housing toform a switch module, said housing having an external shape to bereceived by said opening in said case, a pair of wiring terminalssecured to said housing to be accessible to the exterior of saidenclosing case when said switch module is inserted into said openingtherein, and means connecting the current carrying members of said reedswitch unit to said pair of wiring terminals.
 2. The combinationaccording to claim 1 together with permanent magnet means secured withinthe housing of said switch module adjacent said switch unit and on aside thereof opposite said electromagnet when said module is inserted insaid opening in said enclosing case, and wherein said permanent magnetmeans produces a magnetic flux path within said switch unit to bias themagnetically operable contacts thereof.
 3. The combination according toclaim 1 together with a connector module inserted into said opening insaid case to provide a readily removable electrical connection to saidelectromagnet, plug-in electrical connector means mounted on said coiland cooperating plug-in electrical connector means mounted on saidconnector module in engagement with said connector means on said coil, apair of wiring terminals secured to said connector module to beaccessible to the exterior of said enclosing case when said connectormodule is inserted into said opening therein, said connector modulehaving an outwardly extending key formed thereon to be cooperativelyreceived within a complementally formed recessed keyway in said case,and having a secondary keyway formed therein to cooperate with anoutwardly extending secondary key formed in said enclosing case, saidsecondary key being of a form preventing insertion of said switchmodules therein.
 4. The combination according to claim 2 together with apair of shallow recesses formed in opposite external sides of thoseswitch module housings in which permanent magnets are mounted,projections extending outwardly from said recesses and a pair ofmagnetizable members secured within said recesses at opposite externalsides of said switch module housings by deforming said projections overouter surfaces of said magnetizable members to provide self-containedmagnetic shielding for each switch module.
 5. The combination accordingto claim 1 wherein said insulating housing of said switch module has alateral opening formed therein on the side adjacent said pole pieces ofsaid electromagnet to expose a portion of said switch unit directly tosaid electromagnet.
 6. An electromagnetically operated multipoleconvertible reed relay comprising, in combination; a hollow insulatingenclosing case; a coil mounted in said case to extend axially front torear of said case; an axial opening in said coil; a magnetizable core insaid opening in said coil and extending end-to-end of said coil; a pairof U-shaped magnetizable pole pieces overlapping the opposite ends ofsaid coil and extending toward each other along the opposite exteriorsides of said coil; openings in the front of said enclosing case onopposite sides of said coil; and a plurality of individually removableswitch modules inserted within said openings in said case to extend intosaid case alongside of said pole pieces at the exterior sides of saidcoil, each of said switch modules comprising a molded insulatinghousing, a sealed electromagnetically operable reed switch mountedwithin said housing, a pair of wiring terminals carried by said housingat a forward end to extend out of said enclosing case, and meansconnecting said wiring terminals to the respective contacts of the reedswitch mounted within the housing.
 7. The combination according to claim6, wherein the insulating housing of each of said switch modules has alateral opening formed therein on the side adjacent said pole pieces ofsaid electromagnet to expose a portion of said reed switch unit directlyto said electromagnet.
 8. The combination according to claim 6, togetherwith an indicator member mounted within said case to extend along oneside of said electromagnet and into a window formed in an exteriorsurface of said case, said indicator being movable toward and away fromsaid electromagnet, means to bias said indicator away from saidelectromagnet to a first position within said window, and wherein saidindicator is attracted to said electromagnet upon energization thereofto cause said indicator to move to a second position within said window.9. The combination according to claim 6, wherein the winding ends ofsaid coil are terminated at plug-in type electrical connector means,first portions of said connector means being secured to an exteriorsurface of said coil and exposed within one of said pockets of saidcase, second cooperating portions of said connector means secured to aninsulating housing removable inserted into said pocket, said housingfurther having a pair of wiring terminals secured thereto exposed to theexterior of said case when said housing is seated within said pocket,and conductor means electrically connecting said other portions of saidconnector means to said wiring terminals within said housing.
 10. Thecombination according to claim 9, wherein said conductor means comprisesrectifier means for rectifying supply alternating current to provideenergizing direct current for said coil, said rectifier having its inputterminals connected to said wiring terminals and its output terminalsconnected to said second cooperating portions of said connector means.11. The combination according to claim 10, wherein said rectifier meansis a full-wave rectifier bridge and further comprises a zener diodeconnected between an output terminal of said rectifier bridge and theassociated other portion of said connector means to be in series withsaid coil and oppose the coil current when electrically connectedthereto.
 12. The combination according to claim 6, wherein said corecomprises a plurality of magnetizable laminations loosely stacked withinthe central opening of said coil.
 13. In a convertible electromagneticswitching device, the combination comprising: an insulating enclosingcase having a cavity with openings to opposite ends thereof, a centralweb extending across a first open end of said case to divide the openingtherein into a pair of openings, and a pair of inwardly extending wallportions at the second open end of said case to reduce the openingtherein; a first magnetic pole piece inserted within said cavity fromsaid second end to abut said central web and having portions extendingtoward said second end; a coil member inserted within said cavity fromsaid second end to abut said first pole piece between said extendingportions, a central opening in said coil member aligned with saidopening in said second end of said case and extending through said coilto open to said first pole piece; and at least one foot portionextending outwardly of said coil member, said foot portion havingplug-in electrical connector means secured to an exterior surfacethereof and connected to the windings of said coil, said connector meansbeing in alignment with a respective one of said pair of openings ofsaid case and within said cavity thereof; a core comprising a pluralityof loosely stacked magnetizable laminations inserted within said centralopening of said coil through said opening in said second end of saidcase, said core abutting said first magnetic pole piece; a secondmagnetic pole piece inserted within said cavity from said second end toabut an opposite end of said core, said second magnetic pole piecehaving portions extending along opposite sides of said coil toward saidextending portions of said first pole piece and in alignment therewith;a mounting plate for mounting said switch device to a panel secured tosaid second end of said enclosing case to close the opening therein;biasing means disposed within said opening in said second end, saidbiasing means being compressed between said mounting plate and saidsecond magnetic pole piece to bias said magnetic pole pieces, core andcoil tightly against said central web within said cavity; meansremovably inserted into said cavity through a respective one of saidopenings in said first end to cooperatively engage said connector meansfor electrically connecting said coil winding to an energizing supplysource; and at least one magnetically operable switch module removablyinserted into said cavity through either of said openings in said firstend to be operated upon energization of said coil.
 14. In combination,an operating coil for an electromagnetically operable switching deviceand a plug-in connector module for connecting said coil to an electricalsupply source, said coil having plug-in electrical termination meansexposed to an exterior surface thereof and said connector moduleincluding an insulating housing, plug-in connector means supported onsaid housing, wiring terminal means supported on said housing, and afull wave rectifier bridge within said housing, said bridge having itsinput terminals connected to said wiring terminal means and its outputterminals connected to said plug-in connector means, and wherein anelectrical supply source is connected to said wiring terminals on saidconnector module and the latter is connected to said coil by means ofcooperable plug-in engagement between said plug-in connector means onsaid module and said plug-in termination means on said coil to supplyrectified current to said coil.
 15. A convertible electromagneticswitching device comprising in combination; a hollow insulatingenclosing case; an electromagnet mounted within said case, saidelectromagnet including a coil having an axial opening therethrough, amagnetizable core extending through said axial opening and a pair ofmagnetizable pole pieces overlapping the respective ends of said coiland said core and extending toward each other along opposite externalsides of said coil; at least one opening in said case adapted to receiveat least one magnetically operable sealed switch means therein, at leastone of said switch means removably inserted into said opening in saidcase to extend alongside of said magnetizable pole pieces at theopposite external sides of said coil of said electromagnet within saidcase to be operated upon energization of said electromagnet, and anindicator member mounted within said case alongside said electromagnetfor removing toward and away from said electromagnet, said indicatormember hAving a portion extending beyond said electromagnet and into awindow opening formed in said case, means for biasing said indicatormember to a first position within said window, and wherein saidindicator is attracted to said electromagnet upon energization thereofto cause said portion within said window to move to a second positiontherein against the bias of said biasing means.